The presence of toxic substances in the environment may be an important factor contributing to the poor health of honey bee colonies globally. Agrochemicals are of particular interest because they often are accused of causing sublethal effects in individual bees and the bee colony, possibly even leading to the loss of entire colonies and even apiaries (Maini et al., 2010; Desneux et al., 2007).
Honey bees are excellent bioindicators of environmental pollution (Celli and Maccagnani, 2003). Thus, it is easy to imagine that wild pollinators (or other animals occupying the same ecological niche) present in polluted areas will suffer outcomes similar to those experienced by honey bees in the area. For this reason, the research community should work to limit the hazard of toxins to honey bees and, by doing this, will help to protect wild pollinators.
The risk assessment addressing the potential risk for pollinating insects from the use of Plant Protection Products (PPPs) is comprised by oral and contact LD50 (Lethal Dose that kills 50% of the population), toxicity exposure ratio (TER) and results of semi-field and field trials (e.g. direct or delayed bee mortality) highlighting the impact on brood development, foraging abilities, etc.
The registration of agrochemicals requires that specific toxicological tests be performed on honey bees, such as those required by the US Environmental Protection Agency (US EPA, 1996) and the European Organisation for Economic Co-operation and Development (OECD, 1998a; OECD, 1998b). These tests must follow specific protocols in order to (1) assess the level of selectiveness of the pesticide to honey bees and (2) satisfy a given country’s pesticide regulatory requirements. They must be performed in Good Laboratory Practices (GLP).
The present chapter is not a proposal of guidelines but rather a compendium of methods for testing toxic effects of agrochemicals and other compounds on honey bees. These methods may be used in scientific studies and in official risk assessment schemes where appropriate or where consistent with a given government’s requirements. To be used for the latter, the test should undergo regulatory testing and risk assessment systems in order to be properly validated. Nevertheless, both OECD 75 (tunnel test) and acute toxicity standards (OECD 213 and 214) have not been ring-tested despite that they are referenced by all OECD members as standard methodologies.